ASNT NDT Level III Basic flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Penetrant testing limitation

Detects only surface-breaking discontinuities; porous or rough surfaces can trap penetrant and produce false indications, so surface condition must be controlled.

Radiography sensitivity limit

Detects volumetric changes in density or thickness; tight planar defects oriented parallel to the beam may go undetected.

Ultrasonic testing strength

Detects internal planar defects such as cracks and lack of fusion when the beam is oriented perpendicular to the defect surface.

Magnetic particle applicability

Limited to ferromagnetic materials; detects surface and near-surface discontinuities. It cannot inspect austenitic stainless steel or aluminum.

Eddy current applicability

Requires electrically conductive material; detects surface and near-surface flaws and is sensitive to conductivity, permeability, and lift-off changes.

Acoustic emission principle

A passive technique that detects transient elastic waves released by growing defects under applied stress; requires loading of the part.

Visual testing role

First-line inspection method; direct visual is limited by illumination, resolution, and access, while remote visual uses borescopes and cameras.

Radiographic film density range

Film density is typically held between 2.0 and 4.0 for X-ray inspection, depending on the applicable code and film class.

Method selection by defect location

Surface-breaking flaws favor PT, MT, ET, or VT; internal volumetric flaws favor RT or UT; internal planar flaws favor UT.

Material constraint on method

MT requires ferromagnetic material, ET requires conductive material, and PT requires a nonporous, clean surface.

Geometry constraint on method

RT needs access to both sides, UT needs contact or immersion access, and PT needs surface exposure to penetrant and developer.

UT versus RT for planar flaws

UT is generally superior for tight planar defects and thick sections; RT is superior for complex geometries and permanent documentation.

Eddy current tubing application

Well suited to inspecting tubing and thin-wall heat exchanger tubes from the inside surface for cracks, wall loss, and support plate effects.

Acoustic emission application

Suited to continuous monitoring and locating active defects in large structures such as pressure vessels and storage tanks under load.

Probability of detection factors

Depends on flaw orientation, size, and geometry, plus inspector technique and method sensitivity; method sensitivity is not absolute.

Method comparison criteria

Compare methods on cost, speed, coverage, sensitivity, and the ability to produce a permanent record of the inspection.

Level I responsibilities

Performs specific calibrations and tests under supervision and reports results; does not independently interpret or accept test results.

Level II responsibilities

Performs and interprets tests, directs Level I work, and may be responsible for on-the-job training of Level I personnel.

Level III responsibilities

Selects methods, develops and approves procedures, interprets codes and standards, and certifies personnel within the organization.

Qualification versus certification

Qualification is the demonstrated ability to perform a method; certification is the written attestation of that qualification by a certifying authority.

Certification scope

Certification is method-specific and level-specific; a Level II in UT is not certified in RT unless separately qualified.

Recertification requirement

Recertification is typically required periodically, often every three to five years, and may require re-examination or documented continuing experience.

Procedure approval

Written procedures must be approved by a Level III and must be available to the inspector performing the test.

Code versus specification

A specification states requirements a product must meet; a code is a collection of mandatory rules referenced by law or contract.

Standard versus recommended practice

A standard is a consensus document that may be referenced by a specification; a recommended practice is advisory and not mandatory.

Document hierarchy

Typical order of precedence is contract, code, specification, standard, procedure, and work instruction.

Acceptance versus rejection criteria

Acceptance criteria define the maximum allowable discontinuity size or indication level; rejection criteria define what must be rejected.

Calibration traceability

Reference and calibration standards must be traceable to a recognized national standard and checked at defined intervals.

Ferromagnetic materials

Include iron, carbon steel, and many alloy steels; austenitic stainless steel and aluminum are nonmagnetic and cannot be magnetically inspected.

Castings and forgings discontinuities

Castings can contain shrinkage, porosity, and hot tears; forgings can contain laps, seams, and forging bursts.

Weld discontinuities

Include porosity, slag inclusions, lack of fusion, lack of penetration, undercut, and cracks, each with different detectability by method.

Grain structure effect

Coarse-grain austenitic welds scatter ultrasound and reduce detectability; grain size and structure affect ultrasonic attenuation.